Fiocchi in U.S. Pat. No. 5,185,970 discloses a conventional expanding device for supporting grinding sleeves. The expanding device has “a shaped shaft which concentrically supports a plurality of mutually facing disks which can slide in an axial direction and which are rigidly rotationally connected with the shaft. The disks define, between one another in cooperation, a plurality of peripheral seats for the accommodation of elastic rings which can expand radially upon the axial compression of the disks. The elastic rings are suitable for engaging the inner surface of an emery cloth sleeve.” Abstract of U.S. Pat. No. 5,185,970.
A hand tool must be used to adjust that shaft which in turns expands or contracts those elastic rings. For some people, hand tools are difficult to use for such small objects.
In U.S. patent application Ser. No. 09/267,175 (now allowed  U.S. Pat. No. 6,083,086) and assigned to applicant, Technicor, Inc., the inventor Hacikyan discloses “an expanding device for supporting grinding sleeves. The device has a cylindrical member with an outer surface, an interior chamber, an expanding chamber, and a locking mechanism. The outer surface receives the grinding sleeve and has a first outer diameter of D. The interior chamber receives a rotatable shaft and has a second outer diameter of I, which is less than D. The expanding chamber comprises an expanding material that expands and contracts based upon pressure applied thereon and has a third outer diameter of H and an inner diameter of J, wherein H and J are both greater than I and less than D. The locking mechanism has an open position and a closed position and requires no hand tool to alter its position. When the locking mechanism is in the open position the locking mechanism applies a pressure P to the expanding chamber so the first outer diameter is D, the second outer diameter is I, the third outer diameter is H, and the inner diameter is J. In contrast, when the locking mechanism is in the closed position the locking mechanism applies a pressure Z, which is greater than P, to the expanding material so the first outer diameter and the third outer diameter expand, and the second outer diameter and inner diameter contract.” The present invention is a preferred embodiment of this embodiment.